The vibration parameters of the generator set are important indicators for monitoring its stability. In order to measure high, medium, and low frequency vibrations of medium-sized hydroelectric generating units, a low-frequency compensation circuit designed according to the frequency response compensation principle of the vibration sensor, extending the frequency characteristics to the region of low frequencies. The mathematical representation of the vibration sensor is magneto electric droplet instrument and designed a compensation circuit for it introduced in detail. Amplitude-frequency behavior and mathematical models pertaining to the sensor before and after compensation were compared and examined individually. The experimental setup results show that this design can expand the amplitude-frequency range into the low-frequency domain and has desirable sensitivity and linearity.